3. How many dots will there be in the 8th
figure?
QUESTIONS 1 TO 10 ARE WORTH
3 MARKS EACH
1. Find the value of
(1 ÷ (2 ÷ 3) ÷ (3 ÷ 4) ÷ (4 ÷ 5) ÷ (5 ÷ 6))
(A)
(B)
(C)
(D)
(E)
2
3
4
5
6
(A)
(B)
(C)
(D)
(E)
2. Find the number represented by the
last figure.
42
44
46
48
None of the above
4. A new operation is defined as
𝑀 ∀ 𝑁 = 4𝑀 − 3𝑁
Find the value of 𝑥 in 𝑥 ∀ 1 = 17.
(A)
(B)
(C)
(D)
(E)
(A)
(B)
(C)
(D)
(E)
13
31
32
23
None of the above
SEAMO 2020 Paper B © SEAMO PTE LTD
1
3
4
5
6
7
5. In the figure below, 𝐴𝐵𝐶𝐷 is a square, 7. A prime number is a whole number
that has exactly two positive factors,
𝐵𝐶𝐸 is a straight line where 𝐶𝐸 = 𝑎. It
1 and itself.
is given that the shaded region 𝑦 is
larger than the shaded region 𝑥 by
Examples of prime numbers include
5 𝑐𝑚2.
2, 3,5,7,11,13, …
The sum of 2 prime numbers is 34.
Find their smallest possible product.
(A)
(B)
(C)
(D)
(E)
Find the length, 𝑎.
(A)
(B)
(C)
(D)
(E)
7 𝑐𝑚
8 𝑐𝑚
9 𝑐𝑚
10 𝑐𝑚
None of the above
8. Find the value of 𝐵.
6. The diagonal of a square is 12 𝑐𝑚 as
shown below. What is its area?
(A)
(B)
(C)
(D)
(E)
48
54
72
88
93
(A)
(B)
(C)
(D)
(E)
72
84
88
94
96
9. How many numbers are there in the
sequence below?
68 𝑐𝑚2
72 𝑐𝑚2
74 𝑐𝑚2
76 𝑐𝑚2
80 𝑐𝑚2
4, 10, 16, 22, 28, … , 64
(A)
(B)
(C)
(D)
(E)
2
8
10
12
14
None of the above
SEAMO 2020 Paper B © SEAMO PTE LTD
10. Marvin wrote the following sequence 13. Nutcharat drove from Chiang Mai to
on the whiteboard.
Bangkok at a speed of 120 𝑘𝑚/ℎ. She
then
returned from Bangkok to
1, 2, 3, 4, 5, 6, 7, …
Chiang Mai at a speed of 80 𝑘𝑚/ℎ.
What is the 177th digit he wrote?
(A)
(B)
(C)
(D)
(E)
What was her average speed for the
entire trip?
1
2
3
4
5
(A)
(B)
(C)
(D)
(E)
QUESTIONS 11 TO 20 ARE WORTH
4 MARKS EACH
93 𝑘𝑚/ℎ
94 𝑘𝑚/ℎ
95 𝑘𝑚/ℎ
96 𝑘𝑚/ℎ
100 𝑘𝑚/ℎ
11. How many digits are there in the
14. Emma’s wallet was stolen. Adam, Ben
product below?
and Charles were the suspects.
111 111 111 × 111 111 111
(A)
(B)
(C)
(D)
(E)
Adam: “Ben stole the wallet!”
Ben: “Not me!”
Charles: “It wasn’t me.”
13
14
15
16
None of the above
Given that only one person told the
truth, who stole the wallet?
(A)
(B)
(C)
(D)
(E)
12. Find the value of
1 − 2 + 3 − 4 + 5 − 6 + 7 − ⋯ − 2018
+ 2019
(A)
(B)
(C)
(D)
(E)
840
1010
1060
2000
2018
SEAMO 2020 Paper B © SEAMO PTE LTD
Adam
Ben
Charles
Adam and Ben
Impossible to determine
15. What is the largest 4-digit number
that is a common multiple of 5 and 8?
(A) 9900
(B) 9920
(C) 9940
(D) 9960
(E) None of the above
3
16. What is the first number in the 10th 18. The school rented some boats for 48
row in the following array?
students to go on a boat ride.
A small boat fits 3 students and costs
$4 to rent. A big boat fits 5 students
and costs $6 to rent.
What is the minimum amount of fees
the school paid to rent the boats?
(A)
(B)
(C)
(D)
(E)
(A)
(B)
(C)
(D)
(E)
163
165
167
169
171
$54
$55
$56
$57
$58
19. There is a basket of apples.
At first, 2 more than half of the apples
are removed.
17. In Mathematics "𝐴 > 𝐵" means 𝐴 is
larger than 𝐵 ; "𝐴 < 𝐵" means 𝐴 is
smaller than 𝐵.
Then, 2 less than half the remaining
number of apples are removed.
Given that:
In the end, 20 apples remain.
𝐴 = 98765 × 87654
How many apples were there in the
basket at first?
and
𝐵 = 98756 × 87663
(A)
(B)
(C)
(D)
(E)
Which of the following is true?
(A) 𝐴 > 𝐵
(B) 𝐴 < 𝐵
(C) 𝐴 = 𝐵
76
72
64
58
48
(D) Impossible to determine
(E) None of the above
4
SEAMO 2020 Paper B © SEAMO PTE LTD
20. How many squares are there in the 23. The sum of two numbers, 𝐴 and 𝐵,
4 × 4 grid?
is 42. If 𝐴 is multiplied by 5 and 𝐵 is
multiplied by 3, their new sum is 182.
Find the value of 𝐴.
24. A car travels for 10 minutes at half its
full speed. It then travels at full speed
for the next 10 minutes.
(A)
(B)
(C)
(D)
(E)
28
30
32
34
36
If the car travelled 21 𝑘𝑚 altogether,
what is its full speed in 𝑘𝑚/ℎ ?
QUESTIONS 21 TO 25 ARE WORTH
6 MARKS EACH
21. In Mathematics,
25. The figure shows 2 squares of
different sizes. The area of the shaded
region is 25 𝑐𝑚2.
31 = 3
32 = 3 × 3 = 9
33 = 3 × 3 × 3 = 27
34 = 3 × 3 × 3 × 3 = 81
⋯
⋯
Find the perimeter (in cm) of the
shaded region, given that the side
length of the square is a natural
number.
What is the ones digit in 3333 ?
22. By only moving → or ↓ , how many
ways are there to go from 𝐴 to 𝐵
while passing through 𝑋?
End of Paper
SEAMO 2020 Paper B © SEAMO PTE LTD
5
SEAMO 2020
Paper B – Answers
Multiple-Choice Questions
Questions 1 to 10 carry 3 marks each.
Q1
B
Q2
C
Q3
D
Q4
C
Q5
A
Q6
B
Q7
E
Q8
A
Q9
E
Q10
C
Questions 11 to 20 carry 4 marks each.
Q11
A
Q12
B
Q13
D
Q14
C
Q15
D
Q16
A
Q17
B
Q18
E
Q19
A
Q20
B
Free-Response Questions
Questions 21 to 25 carry 6 marks each.
© SEAMO 2020
21
22
23
24
25
3
40
28
84
52
Paper B
1